jul 7, 1937 - Official Japanese Military Invasion of China
Description:
The Japanese launched a full-scale invasion on China, officially starting the war in the Pacific. This led to even more U.S. opposition, especially after Japan left the League of Nations and occupied Manchuria before. Though the U.S. had little trust for the Soviets, them having an ally of both nations attacked led to considerable tensions. This piled on with the fact that the United States would pull support in regards to oil and steel from Japan meant the two were without a doubt at extreme odds.
Involved: China, Soviet Union, Japan, United States
Outcome: U.S. pulls economic ties and Japan leaves League of Nations, Tensions Grow with Chinese Conflict bringing Major Hostility